Awl-feed adjustment for shoe-stitching machines.



W. R. BLAIR. A

AWL FEED ADJUSTMENT PoR SHOE STITGHING MACHINES.

' APLIGATIONTI'LED MAY 24, 1913.

l092,892. .Patented Apr. `14, 1914u MTNESSES: I IN1/EMME.

f @zZ/@ ATTO NES.

vention. Fig. 2 is a side view of the same.

ln itorward, itis Ifrequently desired .to change ity of irregularity in the sewing. Unless vented a certain new and useful Improve' ."ment in Awl-Feed Adjustments for Shoe' Stitching Machines, of which the following is a full, clear,

l tion, in which- WILLIAM R. BLAIR OF ST. LOUIS, MISS GURI, ASSIGNOR TO 4LNIDIS MACHINE COMPANY, ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

AWL-'FEED ADJUSTMENT FOR SHOE-STITCHING IVIAGHIN ES.

To all whom it may concern Be it'known that I, VILLIAM R. BLAIR, a citizen of the United States, residing at city of St. Louis, State ofv Missouri, have 1nand exact description, such as will enable others skilled in the art to which it appertains to make and usethe same, reference being had to the accompanying drawings, forming part of this specica- Figurel is a top view of a portion of a shoe stitching machine illustrating my m- F ig. 3 is a detail in section on line A-A of Fig. 1. Fig. 4 is a section on line B--B of Fig. 1'.- Fig. 5 is a section on line C-C of Fi 2.

lilly invention relates to sewing machines, and specifically to an improved form of adjustment for regulating the stroke ofv the :feeding awl, and is designed as an' improvement upon y,the device illustrated and described in patent to Pedersen, No. 811,582, of February 6, 1906.

The principal object of lny invention isto provide an accurate and Ie'aily-manlpulated mechanism for adjusting t e length of the stroke of the feeding awl in shoe stitching machines whilelthemachine is in operation.

Another object of my invention is to provide a means for taking up wear and slight displacementsl in the awl shifting mechanism, and adjust the location of the zone of the awls movement.

A further object of my invention is to provide a stitch adjusting mechanism by means of which the machine may be adjusted accurately for stitches of various predetermined lengths.

Further objects of, my invention will be obvious or hereinafter pointed out.

In the use of shoe stitching machines wherein the wozl't is i'ed orward'by a shiftawl which engages tle work and carries the length of the stitch while the work -is on the machine. If the machine is stopped While the stitch is being adjusted, there is an appreciable loss of time and the probabilthe operator is quite familiar with lthe particular machine, itis frequently necessary to Speciiication of Letters Patent. appiieation'ied may 24, 191s.

Aof frame l, andthe former of which pending from Patented Ap1n14, 1914. seriai'No. 769,703.

malte experimental adjustmentbefore the proper length of stitch is obtained. Furthermore, as the machine is used and becomes somewhatworn the same extent of adjustment will not produce the same variation in the stitch.

From an inspection of the drawings, it will be understood that 1 is a portion of the frame of the machine, 2 a slotted cam, 4 the awl shifting lever which is oscillated horizontally by the enga-gement of a roller 5 carried on its rear end and constituting a bearing member operating in the slot 'of cam 2.

6 is a square rock shaft which is actuated through link 7 to give rotary movementl to the collar 9 which is mounted to rotate therewith but slidable longitudinally thereon. Collar 9" carries the awl bar in which is mounted the awl 8. The rotary movement of collar 9 with shaft 6 gives the awl bar and awl an oscillatory movement. The forward end 421 of the awl shifting lever 4 engages the collar 9, and upon the horizontal oscillation of lever 4 the awl will be shifted horizontally on rock shaft 6 to feed the work when it is engaged by the awl. Shifting lever 4 is provided with a slot 4* which is disposed parallel with the longitudinal axis of lever 4. Lever 4 is provided with upper and lower bearing faces, the latter of which rests upon a proper bearing portion pro- Deshiftable plate 11 is a fulcrum pin 12 which is provided with a bushing 14, contacting with the sides of slot 4b, and forming a bearing for the pivotal movement of the awl shifting lever 4. Fulcrum pin 12 carries a" bearing plate 15 which contacts with a bearing surface on the frame 1, holding lever 4 and shiitable plate 11 in contact upon frame 1. A pin 16 is mounted in frame l and operatesin 'an arcuate slot 17 in lever 4. The purpose of this pin and slot engagement is to prevent longitudinal movement of lever 4, but the width of slot- 17 is sufficient to vaccommodate the slight variations in' arcuate movement relative to pin 16 due to variations in the oscillation of lever 4. Shifting plate 11is provided on its. upper surface with rack teeth which are engaged by a pinion 18 carried upon a shaft 19 mounted in bearings 20 and adjustable by means of the thumb screw 21. Upon the vides a bearing for a shiftable plate 11.

or portions sprung,'

desired rotation of pinion 1S by thumb screwv 21, shiftable plate 11 will be shifted longitudinally of lever 4, thereby changing the fulcrum point of lever 4 on fulcrum pin by the shifting of said pin in slot 4b. This shifting of the fulcrum point of lever 4 necessarily varies the length of the stroke of the end 4 of said lever, and consequently the length of stroke of ayvl S. Thumb screw 91 is provided with a scale Q4 by means of which the lforegoing adjustment may be regulated, the scale being arranged to indicate the various lengths of stitches.

To e'liect the desired adjustment of the stitch, it is not necessary, by virtue of this improved adjusting mechanism, to stop the machine While the pivot is being adjusted. rfhis is a highly desirable feature inasmuch as it-is frequently desired to change the length of the stitch While the Work is on the machine. Moreover', this adjustingmeans provides a very accurate adjustment, by which stitching of the desired length may be secured positively and Without experimental adjustments.

As illustrated in Fig. 5, the outer bearing Q0 is provided with a spring pressed pin which. is adapted to engage in any of a series of depressions 26 in the inner face of thumb screw 21, whereby the parts are properly centered and the adjust-ing members 'retained against displacement.

Upon continued use of the machines, it frequently occurs that the forward end 4 of lever 4 and the collar 9 become worn at their points of bearing. This necessarily renders the movement inaccurate and the stitch irregular. Furthermore, the forward end 4 of lever 4 frequently becomes sprung due to the resistance encountered by the lever in its operation of feeding the Work. rIhese displacements of parts would change the Zone of the aivls movement and thus affect the accuracy of the adjustment of the stitch so that it would not correspond tothe indications of the scale 24. In order to compensate for these inaccuracies, I provide the adjusting means illustrated in Fig. 4 whereby the displacement of parts may he taken up. As illustrated in section in said last named figure, it Will be seen that roller 5 is carried on an eccentric pin Q7 pivotally mounted in link 4 and secured by a jam nut 28. lVhen it is desired to take up any inaccuracies in lever 4, jam nut '2S may be loosened and eccentric pin 27 rotated so as to shift roller 5 laterally of lever 4, and thus give end 4a the proper adjustment.

From the foregoing, it will be understood that my invention comprises a simple adjusting device by virtue of which the stitch of the machine may be adjusted While the machine is in operation, and stitches of a predetermined length may be positively and accurately secured.- Furthermore, a means 'is provided whereby the parts' may be adjusted to maintain the proper coordination between the adjusting scale and the work feeding mechanism.

I am aware that modifications may be madeJ in the device shown, and I, therefore, intend that my invention as claimed be construed to cover all obvious modifications.

What I claim is:

1. In a machine of thel class described, a Work feeding aWl, ashifting lever for the same, a fulcrum pin upon which said, lever is pivoted, means for shifting` said pin to vary the extent of operation of said lever, a scale adapted to indicate the extent of operation of said lever, means for oscillating said lever, and means for adjusting the Working position of said lever circumferentially relative to' said fulcrum pin for the purpose described.

2. In a machine of the class described, a Work feeding awl, a. shifting lever for the same, a cam for operating the shifting lever, a. bearing member carried by said shifting lever and cooperating with saidk cam, and Vmeans wherebysaid shifting lever may be adjusted relative to said bearing member for the purpose described.

in testimony whereof I hereunto atix my signature in the presence of two Witnesses, this 19th day of May, 1913.

VILLIAM R. BLAIR.

Witnesses M. I. SMITH, .Inssna CLARK.

he obtained. for rive cents camu-by addressing the Commissioner of Patents,

Washington, D. G, 

